The present invention relates to releasable locking or latching devices and more particularly to ball type locking devices.
Ball type locking pins are used in many different applications where two elements are to be releasably secured together. In a typical ball type locking pin, locking balls are held within the pin and move radially with respect to the pin axis between outwardly projecting operative or locking positions, and inward inoperative or unlocking positions.
FIGS. 4 and 5 of the drawings illustrate two typical ball locking pins, with particular emphasis on the structure used to retain the locking balls and mechanisms for holding the balls in locking positions.
In FIG. 4, a headed, axially slidable actuator shaft is used, with an enlarged head H at the actuator end that is used to engage and hold the balls in outward projecting locking positions. The headed end of the actuator shaft makes single point type contact with each ball, and with extended use the point contacts wear and deform the head. The result is the deformed head will become progressively more difficult to move axially within the pin and the lock will become faulty.
In the FIG. 5 prior art ball locking pin, the problem stated above is partially eliminated by shifting the actuator shaft stop contact to a location labeled B, where a shoulder machined into the tubular pin body engages a complementary shoulder formed in the axially movable actuator shaft. A cylindrical surface E is used on the actuator shaft in this arrangement to hold the balls in their outward operative positions. The problem with this configuration is that the actuator shaft must be produced in two or three interfitting sections to fit into the body. This increases production costs. Further the surface E must be slightly less than the bore diameter within the pin body in order to facilitate axial movement of the actuator. The actuator may thus flex and wear to a point where one or both of the balls can easily shift radially to an inoperative position and cause lock failure. The diameter of the surface E also forces use of either a larger diameter tubular body, to carry the desired ball diameter, or a reduced ball size. Either situation is often undesirable.
In both prior art configurations (FIGS. 4 and 5), the balls are retained within a pin body by rims F that are formed by stamping or xe2x80x9ccoiningxe2x80x9d the external surfaces of the pin body around the ball receiving bores. xe2x80x9cCoiningxe2x80x9d results in depressions S formed in the external surface of the pin body, and imprecise, weak rims F that must accomplish the task of holding the balls against escape. The coined rims F will break with extended use. Once the rims F break, nothing remains to hold the balls within the pin body. The balls will drop out and the lock becomes unusable.
Still other forms of ball locking arrangements make use of separate rims or rings that are threaded or otherwise fitted to hold the locking balls in place. This eliminates the problem presented by the coined surfaces but significantly increases production expense.
The present invention thus has for an objective, to provide a ball type locking pin that is simple in construction yet that will function well with extended use.
A further objective is to provide a ball type locking pin that can be constructed from rolled stainless or other appropriate tube materials without requiring longitudinal boring of the pin body for reception of an actuator.
A still further objective is to provide a ball type locking pin that includes an integral locking ball retainer that will withstand extended use.
A yet further objective is to provide a ball type locking pin that may be easily produced in various lengths.
These and still further objectives and advantages may become apparent from the following description, drawings, and appended claims which define preferred embodiments of our invention.